Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where H. Clark Hoagland is active.

Publication


Featured researches published by H. Clark Hoagland.


Cancer | 1972

Age-associated aneuploidy: loss of Y chromosome from human bone marrow cells with aging.

Robert V. Pierre; H. Clark Hoagland

Direct bone marrow chromosome studies were carried out on 165 males, 3 months to 94 years of age. Forty‐one males were found to have 45,X cell lines in their bone marrow. The number of males exhibiting Y chromosome loss correlated with age, but the degree of Y chromosome loss did not correlate with age. The loss of Y chromosome appears to be a permanent event. The longest follow‐up period in this study was 13 months. The incidence of 45,X cell lines in the bone marrow is much greater than that in peripheral blood leukocyte cultures. The presence of 45,X cell lines in the bone marrow or peripheral blood of aging males should be recognized as a common event, and the finding should not be considered evidence for the presence of a specific disease state.


Mayo Clinic Proceedings | 1992

Outcome of Recipients of Bone Marrow Transplants Who Require Intensive-Care Unit Support

Bekele Afessa; Ayalew Tefferi; H. Clark Hoagland; Louis Letendre; Steve G. Peters

To determine the outcome and prognostic factors associated with bone marrow transplantation (BMT), we reviewed the clinical course of 35 adult recipients of such a transplant who were admitted to our intensive-care unit (ICU). This constituted 24% of patients who underwent BMT for treatment of hematologic disorders during the study period. The reasons for admission to the ICU were postsurgical care in 5, respiratory failure in 25, shock in 4, and renal failure in 1. The in-hospital mortality was 20% for the postsurgical patients and 87% for the others. None of the postsurgical patients required mechanical ventilation, whereas 90% of the others did, and the associated mortality was 93%. Infection was the cause of the respiratory failure in all but 3 of the 25 patients and was associated with 95% mortality. Complications that involved multiple organs increased the mortality to 100%. No significant differences were found in age, sex, type of BMT, serologic tests for cytomegalovirus, history of graft-versus-host disease, conditioning regimen for BMT, and duration of stay in the ICU and the hospital between survivors and nonsurvivors. The APACHE II (acute physiology and chronic health evaluation) prognostic scoring system underestimated mortality and had no correlation with the duration of stay in the ICU or the hospital. Vasopressors, total parenteral nutrition, and transfusion of blood components in the ICU had no influence on the outcome. Open-lung biopsy was helpful in making specific diagnoses, and pulmonary artery catheters were used in most patients to guide therapy but did not improve survival.(ABSTRACT TRUNCATED AT 250 WORDS)


Mayo Clinic Proceedings | 2001

A long-term retrospective study of young women with essential thrombocythemia

Ayalew Tefferi; Rafael Fonseca; Denise Pereira; H. Clark Hoagland

OBJECTIVE To describe presenting clinical manifestations, long-term disease complications, prognostic indicators, and outcome of pregnancy for women younger than 50 years with essential thrombocythemia. PATIENTS AND METHODS We retrospectively reviewed the records of all patients with essential thrombocythemia evaluated at Mayo Clinic, Rochester, Minn, between 1969 and 1991 and identified 74 young women (median age, 35 years; range, 18-48 years) with essential thrombocythemia. The diagnosis was based on previously established criteria. Median follow-up was 9.2 years (range, 0.2-26.2 years). RESULTS Overall survival was similar to that of an age- and sex-matched control population. Thrombotic events (except superficial thrombophlebitis) occurred at and after diagnosis in 11 patients (15%) and 13 patients (18%), respectively. A history of thrombosis at diagnosis was significantly associated with recurrent thrombosis (P = .03). A platelet count higher than 1500 x 10(9)/L at diagnosis was significantly associated with gastrointestinal tract bleeding and subsequent development of venous (but not arterial) thrombosis (P = .04). Major hemorrhagic events occurred in only 3 patients (4%) after diagnosis. Only 1 patient developed acute leukemia. Thirty-four pregnancies occurred in 18 patients. Of these, 17 (50%) resulted in live births. Of the 17 patients with unsuccessful pregnancies, 14 had spontaneous abortions, 1 had an ectopic pregnancy, and 2 had elective abortions. Preconception platelet count, thrombotic history, or specific therapy was not useful in predicting pregnancy outcome. CONCLUSION Young women with essential thrombocythemia can expect long survival with a low incidence of life-threatening thrombohemorrhagic complications or acute leukemia. There is an increased incidence of first-trimester miscarriages that may not be influenced by specific therapy.


Cancer Genetics and Cytogenetics | 1984

Hematologic manifestations associated with deletions of the long arm of chromosome 20

Mellar P. Davis; Gordon W. Dewald; Robert V. Pierre; H. Clark Hoagland

We investigated 20 patients with hematologic disorders who had a clone of cells with a deletion of most of a chromosome #20 long arm (20q-) in the bone marrow. Three patients had polycythemia vera (PV), 6 had acute nonlymphocytic leukemia (ANLL), 8 had preleukemia (PL), and 3 had other myeloproliferative disorders. In our laboratory, a 20q- chromosome is found in 6% of patients with PV, 3% of patients with ANLL, and 1% of patients with PL. Among the 6 patients with ANLL and a 20q- abnormality, 3 had erythroleukemia. There were no apparent clinical differences among our patients with 20q- chromosomes compared with other patients with similar disorders who did not have a 20q- chromosome. The breakpoint of the 20q- anomaly, in each instance, was in band 20q11, but it occurred near the centromere at 20q1101 in 16 patients and at the distal part of this band at 20q1109 in 4 patients. Three of the 4 patients with a breakpoint at 20q1109 had PL.


Mayo Clinic Proceedings | 1991

Essential Thrombocythemia in Young Adults

Kristi J. McINTYRE; H. Clark Hoagland; Murray N. Silverstein; Robert M. Petitt

Essential thrombocythemia is typically a disorder of adults in the sixth or seventh decade of life and is characterized by frequent thrombohemorrhagic complications. In young patients, the optimal management of complications is controversial. We studied 56 young adults (33 female and 23 male patients) with a diagnosis of essential thrombocythemia. The mean duration of follow-up was 4.68 years. The mean platelet count at diagnosis was 1,328,000/mm3. Platelet aggregation studies in 21 patients demonstrated hypoaggregation to epinephrine; spontaneous platelet aggregation was present in 4. At diagnosis, 39 patients were asymptomatic, and thrombocytosis was discovered incidentally. Throughout follow-up (up to 20 years), 24 patients remained asymptomatic. Thrombotic complications developed in 24 patients; they were life-threatening in only 3. The most common vaso-occlusive symptoms were migraine headache (in 12 patients) and erythromelalgia (in 3). Minor hemorrhagic complications occurred in six patients, and none was life-threatening. Serious complications (one cerebral and two myocardial infarctions) occurred in three patients, all of whom recovered. Two deaths occurred, neither of which was attributable to essential thrombocythemia. The treatment regimens used were chemotherapy in 9 patients, antiaggregating agents in 7, radioactive phosphorus in 1, the newer platelet-lowering agent anagrelide in 10, and only observation in 29. No treatment-related acute leukemias developed. This series of young patients with essential thrombocythemia, the largest to date, demonstrates a low incidence of life-threatening complications and a favorable long-term prognosis. Therapeutic recommendations should remain conservative, and potential leukemogens should be avoided unless serious complications develop. Anagrelide may be useful in young patients with thrombocythemia who are symptomatic.


American Journal of Hematology | 1998

Anemia After Orchiectomy

Rafael Fonseca; S. Vincent Rajkumar; William L. White; Ayalew Tefferi; H. Clark Hoagland

The decrease in testosterone production associated with bilateral orchiectomy may result in normocytic anemia in men. We sought to determine the effect of orchiectomy on hemoglobin concentration. Patients were evaluated at the Mayo Clinic in 1993 and 1994 and underwent bilateral orchiectomy for prostate carcinoma. All patients were seen by one of the staff urologists. Patients were included if they had a normal preoperative complete blood cell count and serum levels of creatinine, if they remained without disease progression (suppressed prostate‐specific antigen level and no evidence of clinical progression on review), and if they had normal serum levels of creatinine and mean corpuscular volume during the follow‐up period. The patients could have no other cause of anemia. The complete blood cell count, prostate‐specific antigen level, and serum level of creatinine were determined preoperatively and at least once (>90 days) after orchiectomy. Sixty‐four patients were included in the analysis (median age, 68 years). The median decrease in hemoglobin concentration was 1.2 g/dL after orchiectomy. There was a statistically significant difference in the hemoglobin concentration before orchiectomy compared with postoperative values at all the intervals studied, both by the paired group t‐test and the Kruskal‐Wallis test. There is a clinically and statistically significant decrease in hemoglobin concentration after orchiectomy. Knowledge of this phenomenon may prevent unnecessary diagnostic work‐up in men with normocytic anemia after bilateral orchiectomy. Am. J. Hematol. 59:230–233, 1998.


British Journal of Haematology | 2001

A phase II trial of pirfenidone (5-methyl-1-phenyl-2-[1H]pyridone), a novel anti-fibrosing agent, in myelofibrosis with myeloid metaplasia

Ruben A. Mesa; Ayalew Tefferi; Michelle A. Elliott; H. Clark Hoagland; Timothy G. Call; Georgene Schroeder; Soo Young Yoon; Chin Yang Li; Leigh A. Gray; S. Margolin; C. Christopher Hook

The anti‐fibrotic and cytokine modulatory properties of pirfenidone suggest its usefulness in the treatment of myelofibrosis with myeloid metaplasia (MMM). In a prospective study, 28 patients with MMM were treated with oral pirfenidone. Twelve patients completed 1 year of therapy; 13 were withdrawn because of disease progression and three because of drug intolerance. Only one patient experienced a clinically relevant benefit with respect to anaemia and splenomegaly. The overall lack of clinical benefit correlated with no significant improvement in the bone marrow morphological features of the disease. We conclude that pirfenidone has no significant clinical or biological activity in MMM.


Mayo Clinic Proceedings | 1994

Issues in the Diagnosis and Management of Essential Thrombocythemia

Ayalew Tefferi; H. Clark Hoagland

OBJECTIVE To summarize the current trends in the diagnosis and management of essential thrombocythemia (ET) and to discuss the treatment of young and pregnant patients with ET. DESIGN We review our experiences in the diagnosis and management of ET. MATERIAL AND METHODS A definitive diagnosis of ET at initial examination is seldom possible because of the low incidences of associated clonal cytogenetic abnormalities and palpable splenomegaly. The criteria of the Polycythemia Vera Study Group for the diagnosis of ET are provided, as are the clinical and laboratory features that help to distinguish ET from reactive thrombocytosis. RESULTS Patients with ET have an almost normal life expectancy if thrombohemorrhagic complications are controlled. Although a previous history of thrombosis is an established risk factor for further episodes, the adverse effects of extreme thrombocytosis and age are less well defined. Determining which patients require therapy is controversial. The management of young or pregnant patients necessitates special considerations. CONCLUSION Until additional data become available, no strong recommendations can be given in support of or against specific therapy for asymptomatic young patients. We favor treatment in asymptomatic patients with cardiovascular risk factors but not in asymptomatic women who are pregnant or are of childbearing age.


Mayo Clinic Proceedings | 2002

Neutropenic Colitis After Treatment of Acute Myelogenous Leukemia With Idarubicin and Cytosine Arabinoside

William J. Hogan; Louis Letendre; Mark R. Litzow; Ayalew Tefferi; H. Clark Hoagland; Rajiv K. Pruthi; Scott H. Kaufmann

OBJECTIVE To determine the gastrointestinal toxic effects of idarubicin and cytosine arabinoside combination therapy in patients with newly diagnosed acute myelogenous leukemia (AML). PATIENTS AND METHODS We performed a single-institution retrospective analysis of the incidence of neutropenic colitis in patients with newly diagnosed AML receiving idarubicin and cytosine arabinoside combination therapy. Using pharmacy records, we identified 78 patients who received idarubicin during the study period of January 1997 to September 1998 and who agreed to a review of their medical records. Patients with preexisting bowel conditions were excluded from this analysis. We used a strict definition of neutropenic colitis that included clinical findings (severe abdominal pain, diarrhea, hematochezia, and/or peritoneal signs) plus radiographic evidence of bowel inflammation in the absence of an identified bacterial pathogen. RESULTS Of the 78 patients receiving idarubicin and cytosine arabinoside for treatment of AML, 65 were included in this study. We observed neutropenic colitis in 10 of these 65 AML patients. This complication was followed by sepsis in 3 patients and was the major cause of death in 4 of the 8 patients who died. CONCLUSION This analysis suggests that neutropenic colitis is a frequent and serious complication of idarubicin and cytosine arabinoside treatment.


Mayo Clinic Proceedings | 1992

Hemorrhagic Cystitis Complicating Bone Marrow Transplantation

Louis Letendre; H. Clark Hoagland; Morie A. Gertz

Hemorrhagic cystitis is a potentially serious complication of high-dose cyclophosphamide therapy administered before bone marrow transplantation. As standard practice at our institution, patients who are scheduled to receive a bone marrow transplant are treated prophylactically with forced hydration and bladder irrigation. In an attempt to obviate the inconvenience of bladder irrigation, we conducted a feasibility trial of uroprophylaxis with mesna, which neutralizes the hepatic metabolite of cyclophosphamide that causes hemorrhagic cystitis. Of 97 patients who received standard prophylaxis, 4 had symptomatic hemorrhagic cystitis. In contrast, two of four consecutive patients who received mesna uroprophylaxis before allogeneic bone marrow transplantation had severe hemorrhagic cystitis for at least 2 weeks. Because of this suboptimal result, we resumed the use of bladder irrigation and forced hydration to minimize the risk of hemorrhagic cystitis.

Collaboration


Dive into the H. Clark Hoagland's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Peter H. Wiernik

National Foundation for Cancer Research

View shared research outputs
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge